1. Field of the Invention
This invention relates to dust containment guards for electrical and air tools, and in particular to a dust guard for mounting to an angle grinder, circular saw, or the like, that includes a vacuum port for connection to a vacuum hose to pull dust and materials as are generated by tool operation off of a work surface and collect them in a vacuum system
2. Prior Art
Electrical and air tools that incorporate turning blades or wheels for cutting or removing material off from a surface are, of course, well known, as are guards or shrouds for fitting onto a tool to separate an operators hands from a moving tool edge or surface. A common example of such arrangement is found in a skill saw where, when an operator, holding the saw by its handle, pushes the turning tool blade into a section of wood, and lifts a spring loaded shroud by contact with the section of wood edge. The shroud is thereby lifted onto, and travels along, the wood surface where the turning saw blade is cutting. Such guard arrangement is, of course, well known for use with skill saws, and where a skill saw, or a like saw has been used in a shop setting, such has often included a vacuum port for attachment onto a vacuum hose end for drawing dust, as is produced by the blade sawing action, off from the work surface, and with that dust then traveling into a vacuum system.
Angle grinders are, of course, tools that includes a turning blade, and are hand held by an operator. In practice, the operator holds an angle grinder handle and urges the turning blade edge against or into an item or surface, such as a block wall, to cut or saw into and across that item or surface. Such angle grinder mounts the blade to a drive shaft that is journaled through a bore whereto a guard or guards are fitted. In which arrangement, the drive shaft and bore are arranged at a right angle to the handle. In use, the turning blade generates a large amount of dust, for example, as when it is used to cut or saw into a wall, or the like. Where the angle grinder is used to cut or saw along a line drawn onto a wall surface, or the like, it is important that an operator be able to see the turning blade sawing edge so as to direct that sawing edge along the scribed line. Accordingly, it is desirable to provide an arrangement for removing dust as is generated in wall cutting operations that will not hinder an operators visibility of the turning blade sawing edge that is in contact with the that wall surface. Whereas, which arrangement still needs to provide proper positioning of the guard vacuum end so as to efficiently remove the sawed materials.
The invention is in a dust director meets the operators need to have a clear view of the turning blade edge while affording the operator with a view of the work surface. To meet these needs, the invention provides a dust director portable vacuum guard that connects a barrel portion to a vacuum hose where an opposite barrel end can be positioned for efficiently drawing dust and particles off from the wall, or other surface being cut or sawed. Further, the unique features of the invention include: an arrangement for mounting the dust director to an angle grinder by a use of an attachment ring that provides for fastening the dust director guard securely to the angle grinder""s bore while allowing the dust director to be maintained in a swiveling or fixed cutting position, with the attachment ring, sized to be suitable for mounting onto a number of angle grinders, or like tools, as are currently being marketed; an extension cover that is pivotally attached to an open side of the dust director portable vacuum guard housing to be swung open to expose a side edge of the angle grinder blade to enable the cutting or sawing of an inside corner of a masonry wall: and an air baffle that is part of a barrel of the dust director guard that significantly increases the vacuum efficiency in a removal of grinder dust removal from the work surface.
It is a principal object of the present invention to provide a light weight dust director portable vacuum guard for mounting onto a conventional angle grinder, or like tool, that will shield the turning tool blade while allowing the operator to see the work area and tool edge and is connected through a hose to a vacuum to draw materials as are produced by the turning tool blade off from the work surface.
Another object of the present invention is to provide a dust director portable vacuum guard that, when mounted onto a conventional angle grinder, or like tool, provides the operator with the ability to adjust the guard to their personal cutting styles, that is comfortably held by the operator and provides for an efficient dust removal off of a work surface.
Another object of the present invention is to provide a dust director portable vacuum guard arranged for mounting onto a number of commercially available angle grinders, or the like, so as to be capable of swiveling and, alternatively, can be fixed in position relative to a bore wherethrough a turning tool blade drive is journaled, allowing for guard pivoting between a first position where the angle grinder blade can be use to saw along a wall, and where the guard is freed to rotate allowing the blade to turn into and through a corner.
Another object of the present invention is to provide a dust director portable vacuum guard having an open tube as a vacuum barrel with a large attachment end for receiving a vacuum hose fitted thereover, facilitating high volume of suction, and includes a baffle for improving vacuum efficiency.
Still another object of the present invention is to provide a dust director portable vacuum guard that is configured to expose the turning blade edge and sides, giving an operator both good blade visibility and facilitating their guiding the turning blade along a line scribed over a surface and provides even for cutting or sawing into and out of a walls inside corner.
Still another object of the present invention is to provide a dust director portable vacuum guard with an extension cover arranged to cover the entire turning blade that is configured to allow a lifting of the extension cover when the blade is not turning, for cutting inside of a corner, with the extension cover then easily restored to its blade covering attitude after the corner cut is made.
Still another object of the present invention is to provide a dust director portable vacuum guard that allows pivoting of the angle grinder relative to the guard housing to allow the angle grinder blade to cut or saw into a wall inside corner, providing an operator with a blade shield that is easy to use and that provides cutting or sawing versatility.
Still another object of the present invention is to provide a dust director portable vacuum guard that is easy and quick to install onto a conventional portable angle grinder.
The present invention is in a dust director portable vacuum guard that includes a housing with an attachment ring for fitting onto a portable angle grinder, arranged for mounting onto a tool bore, preferably a portable angle grinder. To provide this mountings, the angle grinder cutting blade is first de-mounted from the angle grinder bore, as by turning a mounting bolt that fits through the blade center coupling opening into a drive and is journaled in the grinder bore. The dust director portable vacuum guard includes a grinder bore receiving, hole formed through an inner side wall wherein the attachment ring is pivotally mounted and is held in place by a spring loaded thumb screw. The dust director portable vacuum guard inner side wall is one of a pair of parallel inner and outer side walls that extend at right angles from junctions with a guard vacuum barrel and connect, along rear edges, to a back wall. The vacuum barrel is a straight tube that is arranged for connection, on an exhaust end, to a vacuum hose, and incorporated an air baffle as a component that provides for improved dust collection performance.
The dust director portable vacuum guard includes the attachment ring for mounting an angle grinder bore thereto and is releasable to allow rotation and is formed to couple to the bores of a number of commercially available angle grinders utilizing four equal spaced threaded screw holes. To mount the attachment ring to the angle grinder bore, for positioning the dust director guard at a desired angle to the angle grinder turning blade, two of the tour holes are selected to receive set screws turned therein. Re-positioning of the dust director portable vacuum guard on the angle grinder bore requires only a release of the set screws, a turning of the attachment ring to a desired location on the angle grinder bore, and a re-turning of the pair of set screw into the selected threaded screw holes to appropriately re-lock the dust director guard onto the angle grinder bore at the new, selected position. Further the guard also includes a spring loaded thumb screw located on the backside of the housing and is threaded for turning into the attachment ring, securing the attachment ring to the housing when it is turned therein, and, when turned out of the attachment ring, the attachment ring is allowed to pivot in its hole mounting in the inner wall. So arranged, release of the attachment ring to pivot, allows the operator to position the dust director portable vacuum guard appropriately to afford the operator with good visability of the angle grinder blade as it saws. Further, the thumb screw is spring loaded by fitting the threaded body thereof through a coil spring that is maintained to the screw head end undersurface and housing inner wall surface to maintain it in alignment with the hole through the housing inner wall
The dust director guard further includes an extension cover that, when unsnapped after the grinder is stopped, can be pivoted away from the grinder blade, allowing the blade to be turned into a wall corner, simultaneously cutting the wall on both sides of the corner and into the corner. Whereafter, the grinder is again turned off, the extension cover is snapped back into place, allowing forward cutting to be resumed. Also unique to the dust director guard of the invention, the dust director guide barrel includes an air baffle that channels a dust flow as is pulled off the work area under vacuum, passed into the barrel that directs that flow into a vacuum system. The baffle, in practice, provides for a greater volume of dust collection off of the work area than does an open barrel alone.